Transmission help I Have a 1993 Cadillac Seville STS 4.6 start my engine goes into reverse and works just fine and put it in all four gear may be some time after about 20 minutes of warming up it will start moving in first gear that this does not happen every time and then I go into my override PS 20 and turn it up in my car it drives and shifts very good until I turned the vehicle off i changes the transmission fluid chance of filters and it did not do one thing for the transmission